Selah Reeve Hobbie Tompkins, United States Cavalry officer, was born in Washington, D.C., on July 17, 1864, the son of Charles H. and August Root (Hobbie) Tompkins. He was known as Colonel Tommy, or, privately, as Pink Whiskers. He came from an illustrious military family. His father was a brigadier general and war hero; his grandfather, Col. Daniel D. Tompkins, graduated from the United States Military Academy and fought in the Seminole Wars and the Mexican War; his uncle, also Daniel D. Tompkins, governor of New York during the War of 1812 and later vice president under James Monroe, raised an army with his own funds to protect Manhattan and kept the United States Military Academy in operation. Vice President Tompkins's father, Jonathan Griffin Tompkins, fought in the Revolutionary War. Tommy Tompkins had two brothers, Daniel D. and Frank; the latter commanded the American forces at Columbus, New Mexico, at the time of Francisco (Pancho) Villa's raid and later wrote a revealing book, Chasing Villa. All three brothers attained the rank of colonel and served from the Spanish-American War through World War I. Frank's son originated the Jeep; he served, after West Point, in World War II and Korea. Since his father served as quartermaster general of the United States Army both during and after the Civil War, Tompkins received his early schooling wherever his father was stationed, until 1878, when he was enrolled at the Shattack School, a military academy in Faribault, Minnesota. He was a good student, a fine athlete, and one of the organizers of the school's now-famed drill team, the Crack Squad. Though he graduated in 1883, Tompkins did not stay long enough to get his diploma, for he was eager to attend the United States Military Academy. He arrived at West Point in time for the entrance examinations, but spent the previous evening at a popular drinking spot and the next day failed his English examination by one-tenth of a point, thus shutting himself out of the famed academy.
His father took him to Gen. Philip H. Sheridan, an old friend, who took the problem to President Chester Arthur. Tommy was one year too young for direct commission, but the president said he was born in 1863, thereby making him eligible. His first assignment was as a second lieutenant in the Seventh United States Infantry, then stationed at Fort Laramie, Wyoming, and commanded by Gen. John Gibbon, who had been a classmate of his father at West Point and was a military friend of long standing. Tompkins did not like the infantry and managed a transfer to the Seventh United States Cavalry on March 12, 1886. He got his first combat experience in 1890–91 at Wounded Knee, and he was cited by both Col. James W. Forsyth and Capt. Edward S. Godfrey, his company commander in the Seventh Cavalry. He next served in Cuba, where he met his wife-to-be, Dolores Muller, the daughter of an officer on the staff of Gen. Valeriano Weyler y Nicolau of the Spanish army. They were married on April 5, 1902, and had a daughter the next year; Mrs. Tompkins died on April 5, 1908, during a childbirth complicated by pneumonia. Tompkins served in the Philippines in 1905 and again from 1911 to 1914, but spent most of his career at western posts, including forts Laramie, Riley, Leavenworth, and Sill. He also served in Texas, not only along the border, but at Camp Stanley, Fort Sam Houston, and Fort Bliss. He felt a particular affection for Texas and always considered it his home.
Tompkins was noted for his Victorian courtesies, which were equaled by his use of colorful language and his fondness for liquor. His activities always made headlines, no matter what; when he fell out of a window and broke a leg, banner headlines in Texas and elsewhere carried the story. He led the Seventh United States Cavalry against Pancho Villa in the battle of Juárez in 1919, in Villa's last bid for power. In July of 1927 Tompkins was relieved of his command at Camp Stanley and stationed at Fort Bliss, then the home of the Seventh United States Cavalry. There he was given command of his old regiment, with which he had served for thirty-two years, for his last week of service. He retired on July 17, 1927, after forty-three years in the military. Tompkins died of cancer of the stomach at the station hospital at Fort Sam Houston, Texas, on February 6, 1939.